Behind the term “cancer” is a series of different diseases. What they have in common is a significantly increased growth of the affected cell tissue. This growth is subject to a loss of control of the natural cell cycle.
Healthy cells are subject to a natural balance of growth, division and cell death. In cancer there is an imbalance between these three, genetically determined components. Growth and cell division outweigh apoptosis, the controlled cell death.
Healthy tissue is therefore increasingly displaced. In medical terminology, this is referred to as a malignant tumor or malignoma. A malignant neoplasm or neoplasia can affect any tissue and thus also the cells of the hematopoietic system.
Leukemia, colloquially known as blood cancer, is a malignant proliferation of white blood cells. Benign or benign tumors are also new formations of cells that are only localized and do not form metastases. Metastases are the settlement of malignant cells at different locations in the body.
Benign tissue proliferations are not considered “cancer”. Characteristic features of a benign tumor are also its good differentiability from the surrounding tissue, slow growth, and little to no differentiation from the cells from which it develops. It is often surrounded by a capsule of connective tissue, which can significantly facilitate its surgical removal.
Many benign tumors are incidental findings, such as a lump in the thyroid gland during routine ultrasound scans. While there are usually no symptoms in this case, a meningioma (benign tumor of the meninges) can become neurologically noticeable within a short time. The meningioma exerts pressure on the surrounding tissue and can lead to speech disorders and paralysis.
Rapid action is then required. Further examples are nevi (birthmarks) and so-called lipomas (tumorous fatty tissue proliferation). A benign tumor can also be accompanied by extensive consequential damage such as impairment of organ functions and a risk of degeneration.
Malignant cancer is a tumor consisting of numerous degenerated cells. Its origin can be traced back to a frequently genetically determined loss of control of the cell cycle. Malignant cells multiply uncontrolled and are no longer subject to the biological regulatory mechanism of growth, cell division and apoptosis (controlled cell death).
Cancer cells produce certain growth factors that contribute to the increased formation of blood and lymph vessels. In this way, their rapid reproduction is additionally supported. However, cancer cells do not simply remain in place, but can invade neighboring tissue and spread throughout the body via the blood and lymphatic pathways.
Metastases or daughter tumors develop. Functioning organs are damaged and even lose their function. A rough classification is made between carcinomas, sarcomas and leukaemias as well as lymphomas. While carcinomas are the most numerous and develop from glandular tissue and covering and lining tissue of organs, sarcomas affect the connective, nerve and supporting tissue. In leukemia and lymphomas, on the other hand, the cells of the haematopoietic and lymphatic system are affected.